Choosing Decaf Coffee - Know How The Caffeine Is Extracted

When it comes to enjoying a flavourful cup of coffee without the jolt of caffeine, there are four major decaffeination processes to consider. Let's take a closer look at each technique and the science behind them.

Direct-Solvent Process:

The beans undergo steaming, releasing caffeine and making them more receptive to a solvent. Over the next ten hours, the beans are rinsed with methylene chloride or ethyl acetate to separate the caffeine from the beans. While this method raises concerns for some, it's important to note that brewing coffee at high temperatures significantly minimises the chances of finding any chemical residue in your cup.

Indirect-Solvent Process:

In this method, the beans are soaked in hot water until the water absorbs both the caffeine and other components from the beans. The water is then transferred to a separate tank where it is treated with a solvent, which selectively removes only the caffeine. The caffeine-rich solvent is skimmed off the top, never directly contacting the beans. The flavour-infused water is returned to the tank, allowing the beans to reabsorb the flavours and proteins.

Swiss Water Process:

If you prefer a chemical free decaf coffee, the Swiss Water process is the way to go. This method, pioneered in 1933 and introduced commercially in 1988, starts with steaming the beans to release caffeine. The beans are then soaked in water oversaturated with coffee compounds from a previous batch. As the caffeine is drawn away in the water, the larger caffeine molecules are captured by an activated charcoal filter, while the smaller oil and flavour molecules pass through, preserving the coffee's delightful taste. The beans undergo a slow drying phase to complete the process.

Carbon Dioxide Process:

The latest decaffeination process involves the use of carbon dioxide (CO2) instead of chemicals. Coffee beans are soaked in water and then placed in a sealed stainless steel container. Liquid CO2 is forced into the container, extracting only the caffeine under high pressure. The CO2 solvent is transferred to an absorption chamber where the pressure is reduced, turning the CO2 back into a gas while leaving behind the caffeine. The caffeine-free CO2 can be reused, making this a sustainable method.

What's the Coffee Store's method?

Swiss Water Process, of course. Besides being chemical-free, in keeping with our preference for organic coffee, it does not compromise the flavour we have so carefully developed.